In their simpler form, refrigerator door locks commonly comprise a hasp secured by a pin, bolt or padlock. However, with these locks, a locked refrigerator door can not be unlocked from within, and thus poses a serious hazard. In a more advanced form, refrigerator locks have inside release mechanisms to enable persons inside a locked refrigerator to unlock the door and open it for exit. Such locking assemblies commonly comprise an externally accessible cylinder lock coupled with an inside latch by a rotatable rod such that the inside latch may be rotated between latched and unlatched positions both by a turn of a key from outside of the door and by hand from inside of the door.
With other types of locking assemblies, the latch has been hinged to a housing mounted to the interior side of the refrigerator door and held in place by a ring pin. Again, the latch is rotatable between its latched and unlatched positions by the turn of a key from the outside of the door. For releasing the latch from within the refrigerator, the ring pin is pulled to release the latch. To return the latch to its rotatable position for rotatably latching and unlatching the door, the holes in the housing and the latch are aligned and the ring pin is reinserted.
In another common design, a Z-shaped latch is rotatably mounted to the rotatable rod by a long screw inserted from the interior side of the refrigerator door through a housing to the rod. Again, from outside the door the Z-shaped latch is rotatable between latched and unlatched positions by the turn of a key. From inside the door, the Z-shaped latch is rotatable between latched and unlatched positions by manually unlatching the Z-shaped latch.
Refrigerator door locking systems of the types just described have all had a common problem with respect to thermal conductivity through the refrigerator door due to their metallic composition for strength. In addition, the latch in such locking assemblies often adheres to the door, the jamb or other locking assembly parts when exposed to refrigeration or freezing temperatures. Such adherence, also known as frosting, increases the moment of inertia for the locking assembly and makes ordinary movement of the latch between latched and unlatched positions more difficult. Moreover, the high profile of such locking assemblies along the interior of the door often obstructs movement of carts and catches workers' clothing. The need for the locking assembly to have a low inside profile is particularly apparent where locking assemblies are installed in doors which have a limited range of motion and, in turn, a limited area with which to load and unload a refrigerator.
Accordingly, it is seen that a need remains for a locking assembly for a refrigerator door that inhibits thermal conductivity through the door while retaining structural strength and operational reliability, that resists frosting of the latch either to the door or to other parts of the locking assembly, and that has a low profile. It is to the provision of such therefore that the present invention is primarily directed.